1. Field of the Invention
The present invention relates to a method for manufacturing in an ink tank that retains ink for use in ink jet recording. Also, the present invention is applicable to a copying machine, recording equipment, such as a facsimile machine, communication equipment, office equipment, complex equipment, a printer, and the like that uses the ink jet technologies.
Here, in the specification hereof, the term xe2x80x9crecordingxe2x80x9d means forming not only meaningful images, such as characters, but also meaningless images, such as patterns. The recording equipment includes all kinds of information processing apparatuses or the printer that serves as the output equipment thereof.
2. Related Background Art
As the output equipment of a personal computer, a copying machine, a facsimile, or the like, a recording apparatus of ink jet type is used. As one example of recording means applicable to an ink jet recording apparatus of the kind, there is an ink jet cartridge in which an ink jet recording head is integrally formed with an ink tank that retains ink to be supplied to the ink jet recording head, which is arranged to be exchangeable with respect to the scanning carriage provided for the apparatus.
The ink tank of an ink jet cartridge has in the interior thereof a negative pressure generating element retaining ink therein, which is arranged to exert a desired negative pressure with respect to the recording head. Here, as a structure capable of using contained ink without waste, while exerting appropriate negative pressure as an ink tank, there is disclosed a structure in the specification of Japanese Patent Laid-Open Application No. 07-125232, for example, wherein the interior of the ink tank is divided into almost halves by use of a wall member, and then, a communicative portion is provided between the separation wall and the bottom thereof to supply ink, while a porous member is contained in a chamber (a first container chamber) on the side where the recording head is installed, and ink is directly contained in the other chamber (a second container chamber).
Further, in the specification of Japanese Patent Laid-Open Application No. 08-230209 filed by the applicant hereof, a structure is made applicable to an ink jet cartridge having a recording head provided integrally therefor so as to be more adaptable for change of postures in the delivery distribution, as well as for the environmental changes.
As described above, the applicant hereof has proposed the ink tank structure which is excellent in demonstrating the capability of stable ink supply against the condition of delivery distribution and environmental changes. For the sufficient demonstration of such function of the tank, the following aspects are taken into consideration for the implementation thereof.
In other words, the shape of the first container chamber is such that the dimension in the directions substantially in parallel is made larger than the dimension in the direction orthogonal to the structural plane of the partition plate to be fused and bonded so that the area of the porous member contained in the first container chamber, which exists between the fine communicative portion and the ink supply port connected with a recording head, is easily compressed more than the other area. Moreover, with the structure in which the first container chamber is formed by fusing and bonding the partition plate after the porous member has been contained in the tank container, the contained porous member is in such a configuration that it is scarcely compressed in the direction orthogonal to the structural plane of the partition plate, that is, the restoring force of the compressed porous member does not work greatly in the direction in which the fusion bonded partition plate is compressed to the ink containing chamber side. As a result, the compressivity of the contained porous member is made greater in the direction substantially parallel to the structural plane of the partition plate so as to exert negative pressure with respect to the ink jet recording head.
Along with this arrangement, the porous member is in such a shape before compression that the dimension thereof in the direction of its insertion into the tank container is extremely small as compared with the one in the direction orthogonal to the inserting direction.
However, when the porous member is compressed in the direction orthogonal to the inserting direction at the time of being inserted into the tank, there is a possibility that the compressed porous member is folded right on the center thereof, because the dimension of the porous member is smaller in the direction of insertion than the one in the direction orthogonal to the inserting direction before being contained in the tank. As a result, it becomes difficult to insert the porous member into the tank container in good condition.
With a view to solving the problems encountered in the manufacture of tank as described above, it is the main object of the invention to provide a method for manufacturing an ink tank capable of containing in a tank container a porous member of such a shape that the dimension thereof is extremely large in the direction orthogonal to the direction of insertion into the container as compared with the dimension in the inserting direction by exerting compression greatly on the dimension in the direction orthogonal to the inserting direction, while scarcely exerting compression on the dimension in the inserting direction so as to obtain appropriate compression for generating negative pressure in the tank container.
Also, it is another object of the invention to provide a method for manufacturing an ink tank capable of maintaining the ink supply capability stably irrespective of the condition of delivery distribution and the environmental changes.
It is still another object of the invention to provide an ink tank manufactured by the method of manufacture described above, an ink jet cartridge provided with such ink tank, and an ink jet recording apparatus having such ink tank mounted thereon.
In order to achieve the above objects, the method of the present invention for manufacturing an ink tank comprises the steps of supplying a container having an opening; inserting a porous member into the opening of the container in a state of being compressed; and holding the porous member in the compressed state by fixing a plate member to the opening of the container, and the porous member being in a compressed shape more in the direction substantially orthogonal to the direction of the insertion when the porous member is compressed in the inserting direction into the opening. In this method, when compressing the porous member, the porous member is clamped in the same direction as the inserting direction so as not to allow the porous member to be deformed in the inserting direction, and in such state, the porous member is compressed in the direction substantially orthogonal to the inserting direction.
Further, when fixing the plate member to the opening, the porous member inserted into the opening should preferably be pushed in once.
The porous member is in a shape of flat rectangular parallelepiped having small dimension in the inserting direction as compared with the dimension in the direction substantially orthogonal to the inserting direction into the opening, and the dimension of the porous member in the inserting direction is slightly larger than the dimension of the opening in the inserting direction.
It is preferable to compress the porous member more in the direction X than the direction Y when the dimension of the porous member of flat rectangular parallelepiped is larger in the direction Y than the dimension in the direction X in the two axial X and Y directions orthogonal to the inserting direction.
Also, for the ink tank which is used for the method of manufacture described above, the plate member is a partition plate for dividing the interior of the container into a first container chamber and a second container chamber, and the porous member is contained in the first container chamber; the first container chamber is provided with an ink supply port arranged on the plane facing the partition plate, and an atmosphere communication port; the partition plate is provided with a fine communicative portion in the area facing substantially to the ink supply port; and the area of the porous member existing between the ink supply port and the fine communicative portion is held in higher compression than the other area.
Also, the present invention further encompasses the ink jet cartridge, which comprises an ink jet head being bonded to the ink supply port of the ink tank referred to in the preceding paragraph.
For the aforesaid ink jet head, it is applicable to adopt the one which is provided with electrothermal converting devices to generate ink discharge energy for discharging ink from the discharge ports by utilization of film boiling created in ink by thermal energy applied by the electrothermal converting devices.
Also, the present invention includes the ink jet recording apparatus provided with an ink jet cartridge which is made detachably mountable on the recording apparatus main body.
In accordance with the present invention, it is arranged to clamp the porous member in the inserting direction so as not to allow the porous member to be deformed in the inserting direction when inserting it into the container, and in this state, the porous member is compressed in the direction substantially orthogonal to the inserting direction. Therefore, even if the dimension of the porous member is sufficiently small in the inserting direction before compression as compared with the one in the direction substantially orthogonal to the inserting direction, there is no possibility that the compressed porous member is folded right on the center thereof, hence making it possible to insert it into the tank container in good condition.
Also, after the porous member has been inserted into the container in a state of being compressed, the porous member is pushed in once during the period until the plate member is fixed to the opening of the container, hence preventing the porous member from being expanded and folded, to make it possible to obtain appropriate compression in the porous member thus contained.